1. Field of the Invention
Embodiments of the present invention relate to packaging machines and, more particularly, to an automated packaging machine for filling containers with pills, and associated method.
2. Description of Related Art
Pharmaceutical medicines and associated packaging apparatus are typically subject to relatively strict consumer protection guidelines. For example, pills, capsules, and the like, must be produced and packaged in such a way as to at least meet the minimum sterility requirements mandated by federal regulations. In addition, the pills should be delivered into the packaging such that the contents accurately meet the claimed labeling “count”, i.e., each package includes exactly the predetermined number of pills. Notwithstanding the above, it is also desired to package the product in a mass production operation to offset costs typically attributed to a labor intensive operation in order to provide an economic product.
In the past, pill filling machines have been proposed that provide automated bottle counts by filling a hopper with pills and causing a plurality of the pills to be caught by a pill capturing device, such as an array of rotary slats. The rotary slats drop the captured pills into a plurality of bottles disposed in alignment with the dropping pills. The bottles are distributed along an endless conveyor belt that is timed to advance and stop the bottles according to the filling operation.
Conventional pill capturing devices more particularly include a series of rotary slats each configured to receive, hold, and move a plurality of capsules or pills along a closed path. The rotary slats are typically discs fixed on a rotatable shaft and have a plurality of openings in the outer peripheral edge portion thereof for capturing individual pills. Accordingly, the closed path is arcuate and generally disposed between a pill hopper and discharge area above the conveyor belt. By the rotary action of the slat, the pills move in a direction normal to the conveyor belt. The pill capturing device then generally discharges the pills by rotating the slats, which move corresponding to the closed path, such that the pills fall out of the respective openings at the filling station. The pills are often funneled through a chute that empties into a corresponding bottle.
The “count,” or number of pills in the bottle, is determined by positioning the bottles in the pill dropping zone for a predetermined time. The duration of the filling operation for each bottle corresponds to the number of openings in each slat that the machine is capable of delivering to the bottles per unit of time. The duration of the filling operation, speed of the rotary slats, and configuration of the pill capturing device are used to calculate the count.
Unfortunately, if the pill capturing device fails to capture a pill in each and every cavity or receptacle, or if a pill should mistakenly be diverted, at least one of the bottles can be improperly filled. The conventional solution to this problem is to situate an operator adjacent to the slats to ensure that each receptacle is filled with a pill. If a pill is missing, the operator manually places a pill in the receptacle. Such an approach involves labor costs and can be unsatisfactory for sterility purposes. In addition, the accuracy of the count of each bottle is largely determined by the operator and, as such, a fully and consistently accurate count cannot be guaranteed.
U.S. Pat. No. 6,185,901 to Aylward, which is incorporated herein by reference, provides an exemplary solution to this problem by way of a machine with independently driven rotary slats. The pills are allowed to fall into an exterior receptacle of a rotary slat and, in one embodiment, passed under a rotary brush in an attempt to prevent two pills from being disposed in the same receptacle. A separate counting device is associated with each rotary slat for counting each pill as it falls from the slat into the container. A positive count is provided for each container and improperly filled slats will not affect the total count for that container. If a particular container has a low count, the respective slat can be further rotated to fill the container. Because the slats are independently driven, the other slats can remain stationary to prevent overfilling. Thus, the machine permits an accurate filling of each bottle.
One alternative apparatus is a rotatable drum, as provided in U.S. Pat. No. 4,094,439 to List. The rotatable drum includes a plurality of parallel rows of throughgoing holes that constitute receptacles for dragees. The dragees enter the receptacles in the drum from the interior of the drum at an inner input location, exit to the exterior of the drum at an outer retrieval location, and are filled into bottles. An ordering device facilitates the entry of the dragees into the receptacles, and feeler blades engage the receptacles. If any of the receptacles in an axially extending row do not contain a dragee, one of the feeler blades actuates a bolt pusher, which prevents any of the dragees in the row from being filled into the bottles. Instead, a solenoid and knockout bar empty the receptacles of the row. By preventing the bottles to be filled from partially filled rows of receptacles, the apparatus prevents the different bottles from being filled at different rates.
Undesirably, the additional mechanical components that are required for emptying the partially filled rows of apertures increase the complexity, cost, and likelihood of failure of the apparatus. Additionally, emptying the partially filled rows slows the process of filling the bottles because no pills are dispensed from those rows.
Accordingly, there is a great need for a packaging apparatus which provides an accurate count for each container and operates at a high speed. The apparatus should require a minimum of operator intervention. Additionally, the apparatus should be cost effective, both in initial cost and maintenance costs.